Amazon is planning three new headquarters buildings in downtown Seattle.

The buildings could be 37 stories tall and have up to 3.3 million square feet of space -- the largest development ever proposed in downtown Seattle. They will take up to 8 years to build, reports the Seattle Times.

Architect John Savo of NBBJ, which is working with Amazon on designs, presented some early concept designs to a city review board last night. (PDF here.)